Fuel pump for motor vehicles



June 7-, 1938. E. c. HORTON 2,119,880

FUEL PUMP FOR MOTOR VEHICLES Filed Oct. 9, 1935 2 Sheets-Sheet 1 Tocarburefor Fig.2. 6

' INVENTOR Erwin, C.Hor1:o'n,

'A ORNEYS June 7, 1938. E. c. HORTON FUEL PUMP FOR MOTOR VEHICLES Filed .Oct. 9, 1935 2 Sheets-Sheet 2 INVENTR I Erwm, C. Horirqru BY M v Q1. ATTORNEYS mma Patented June 7 1938 FUEL PUMP Fort MOTOR VEHICLES Erwin C. Horton, Hamburg, N. Y., assignor to Trico Products Corporation, Buffalo,- N. Y.

Application October 9, 1935, Serial No. 44,284

10 Claims. (01. 103-37) This invention relates to a fuel pump for moe tor vehicles and it has for its primary object to provide a pump which will function in a more eificient manner, over heretofore proposed pumps, in furnishing the engine a uniform and constant supply of fuel.

It has heretofore been the practice to operate a fuel pump on its liquid expelling stroke by spring means which maintain the outflowing fuel under an urge for supplying the carburetor with fuel. The return stroke of the pump plunger was mechanically eilected by a lever which was oscillated from the engine cam shaft. During the fuel expelling stroke this lever would be brought into the path of its actuating cam long prior to the plunger completing its fuel feeding stroke, and consequently the pump would be more or less under a constant influence of the cam shaft. This premature operation of the plunger'by the cam was not only objectionable in subjecting the pump to unnecessary wear, but it developed and caused an incessant tapping noise as the cam contacted the lever.

The present invention comprehends means for returning the pumping. member only after the latter has completed a substantial portion of its fuel expelling stroke, whereby the wear on the parts may be reduced to a minimum, the spring means permitted to function uniformly over a prolonged time interval, and the pump and feeding system rendered more efficient and durable.

For a clearer understanding of the present invention, reference is made to the accompanying drawings wherein p Fig. 1 is an elevation of a fuel pump embodying the present invention, one of the cover plates being removed to more clearly depict the operating mechanism. E

i .2 is a vertical sectional view through the Fig'. 3 is a horizontal sectional view through the pump chamber on a plane above the plunger.

Fig. {is a similar view on a plane beneath the plunger. v a

Fig. 5 is a detailed perspective view'of the one form of adjustment for compensating for wear in the transmission mechanism.

Figs. 6 and 7 are diagrammatic views illustrating more clearly an acceptable form of intermittent transmission means.

Fig. 8 is a vertical section through a modified transmission; and

Fig. 9 is a view similar to Fig. 2 through a modified embodiment of the invention.

Referring more particularly to the drawings,

the numeral 1 designates the pump chamber'in which is disposed the liquid displacing or pumping member 2' (which may be of the diaphagm or piston type) for reciprocatory motion, the chamber having an inlet port 3 which is adapted to be connected to a supply tank and which according to the present disclosure, opensinto the. chamber at one side of the plunger 2 through an orifice 4 provided with a non-return valve 5. The outlet port may lead from the same side of the plunger although in the illustrated embodiment the outlet port 6 carries off from the opposite side thereof, the fuel being by-passed by a transfer passage 1 adapted to be closed on the I expelling or up stroke by a valve 8.

On the intaking or down stroke the valve 8 is unseated so as to permit the .transfer of fuel from the under side of the plunger to the upper side thereof. To this end the plunger rod 9 fixedly carries the valve 8 and is connected to the plunger for limited playmovement suflicient to permit the plunger to drag on theintaking stroke while the valve is pulled away therefrom by plunger rod 9 in order to open the transfer passage 1 for the by-passing of the fuel from beneath the plunger. A stop member I0, carried by the plunger rod, overhangs the plunger with sufllcient intervening space to enable such relative movement between the valve and the plunger.

On the fuel expelling stroke the plunger is under the urge of a spring H which maintains the fuel in the outlet port Sunder an urge suflicient to meet. the requirements of the engine to which such outlet port is connected.

The return or down movement of the plunger is mechanically imparted t'hereto in 'a positive manner by intermittently bperatin'gfmeans which is automatically brought into action after a predetermined movement of the plunger by the resilflent means}: I. A dcording'do the showing in Figs. 1' and 2 the power for this return movement is intermittently transmitted from the engine. The plunger rod is provided at its lower end with a cross head I! which has an opening I! in' which an eccentric It operates. The eccentric is positively driven during a partial rotation by intermittently operating means, such as by the mutilated friction gear i5 which, in turn, is driven from a gear l6 that is constantly rotated by the engine. The frictional contact between these gears may be increased by a facing I I and the driven gear l5 may be adjusted with respect to the driving gear to compensate for wear. This compensation may be manually accomplished by a cam l9 which acts in the hollow of a vertically adjustable spindle 21. This spindle is slidable in a vertical guideway 23 and on the spindle is mounted the hub 20 of the gear I. Adjustment of the cam will effect vertical movement of the spindle and adjust the gear l5 toward the gear ii. The cam I3 is carried on a threaded stem II which may be rotated by a tool inserted in the kerf 23 and retained at a given adjustment by a jam nut 24. When the driven gear is being rotated by the driving gear l6, eccentric M will operate in the cross head guideway i3 and impart downward movement to the pump plunger.

The periphery of the driven gear I5 is mutilated or depressed, as at 25, from the true circle of the active peripheral portion 26 so that after the driving gear rides off the active face portion 36, the driven gear will be released from oper ative contact with the driving gear and free to permit the spring ll solely to function on the expelling stroke of the plunger while the driving gear merely idles. The operative contact between the driving and driven gears is preferably maintained to an extent sufficient to move the throw portion of the eccentric ll just across the lower dead center position so that the spring ll may properly move the plunger upwardly and incidentally act to drive the eccentric on such fuel expelling stroke of the plunger to bring the beginning or forward end of the active face portion 26 again into contact with the driving gear l6. This re-engagement between the driving and driven gears is accomplished by the spring i I approximately at'the completion of the liquid expelling stroke of the plunger, or preferably slightly in advance of such completion of the stroke so as to insure the gear l6 taking hold on the driven gear IS in ample time to make the return stroke of the plunger and obviously without imparting any substantial fuel feeding movement to the plunger which might cause a flooding of the carburetor.

In Fig. 9 the fuel pump is embodied in the carburetor 30 and. the liquid expelling stroke of the pump is effected by the spring II. The transmission gears of the operating mechanism may be disposed above the pump chamber, as illustrated, the driving gear 3| being mounted on a rotating shaft 32 of the engine and having intermittent engagement with the driven gear 33. In lieu of having the cross head form of drive, a pitman 34 is connected at one end to a crank pin 35 on the driven gear 33 and at its opposite end to the plunger rod 36. Obviously, the power of the spring H is insufficient to unseat the float closed 'valve of the carburetor.

In practice the plunger rod 36 preferably operates through a packless bearing 45 so as to lighten the burden on the driving part. The fuel which may leak through the bearing 45 into the spring chamber 46 will find its escape into the fluid chamber or reservoir through a passage 41.

As a modified take-up or wear compensating support for the two gears, the adjustable pinion 31 of the driven gear 43 may be urged by a spring 33 toward the driving gear 44 and be carried by a stem 39 for limited play movement as defined by the pinand slot connection 40. .C'he stem is threaded into its support H for manual adjustment which is effected by turning the stem 39 after first releasing the jam nut 42, and after the adjustment has been obtained then the nut is againset against the support 4|, as illustrated. In each form of the invention the positive 76 drive of the pump occurs at widely separated inanaaeo tervals and is substantially co-extensive with the fuel intaking stroke thereof, being preferably increased thereover sufficient to carry the driving connection between the plunger and the driven gear across a dead center position, both at the top and bottom so that the plunger spring will be free to act on the fuel expelling stroke when the driven gear moves out of operative relationship with the driving gear. Thus the operation of the pump insures a positive mechanical return stroke for intaking fuel from the supply tank to the outlet side of the plunger, and a maximum fuel expelling stroke unhindered by a premature coming. into contact with the positive driving element. This enables the pump to operate at a: maximum and renders the same durable.

While the foregoing description has been given in great detail for clearness, it is not the intention to restrict the invention thereby, since the inventive concepts and principles here involved. are capable of embodiment in other physical forms.

What is claimed is:

'1. A pump for maintaining a predetermined supply of liquid in a chamber, embodying a liquid displacing member operable on an expelling stroke to feed liquid to thechamber and on the return stroke to intake liquid from a source of supply, means for yieldably urging and actuating the displacing member on its expelling stroke, means for positively driving the displacing member on its return stroke, said means including a mutilated gearing connecting the driving means to the displacing member for positively drivin the displacing member on its return stroke, said yieldable means acting to bring the gearing int meshing relationship as the displacing membe1 substantially completes its fuel expelling stroke 2. A fuel pump for transferring fuel from th( source of supply to the carburetor of a motor vehicle engine, comprising a chamber and a liquic displacing member operable therein and having 2 maximum liquid expelling stroke and a maximun return liquid intaking stroke, resilient mean: for yieldably imparting the liquid expelling strok to the displacing member, and means for posi tively imparting the return stroke to the dis placing member substantially at the completioi of the maximum fuel expelling stroke, said mean including a rotatable driving member and a ro tatable driven member free of engagement wit? the driving member during the expelling strok to permit the operation of said resilient mean and engageable with said driving member at th completion of the expelling stroke by said re silient means for positively driving :said liqui displacing member during its return stroke.

3. A fuel pump having a liquid expelling stroll and a return liquid intaking stroke, resilier means for yieldably imparting the liquid expe ling stroke to the pump, a driving gear, a drive gear for meshing contact with the driving gea said driven gear having a mutilated peripher portion for non-engagement with the drivix gear co-extensive substantially with the liqu expelling stroke of the pump, said dri en ge also having an active peripheral portion for dri ing engagement with the driving gear to be dl'iVi thereby to impart the return stroke to the pun. and means operatively connecting the driven ge to the pump, said means acting to move the driv gear into reengagement with the driving ge under the urge of said resilient means and su stantially at the completion of the liquid exp ling stroke of the pump.

4. A fuel pump for transferring fuel from a source of supply to the carburetor of a motor vehicle power plant, comprising a chamber, a liquid displacing member operable therein, and having a liquid expelling stroke and a return liquid intaking stroke, resilient means for yieldably imparting the liquid expelling stroke to the co-extensive substantially with the liquid expelling stroke of the displacing member, said driven gear also having an active peripheral portion for driving engagement with the driving gear to be driven thereby for imparting the return stroke to the displacingmember, means operatively connecting the driven gear to the displacing member, said means acting to move the driven gear into re-engagement with the driving gear under the urge of said resilient means and substantially at the completion of the liquid expelling stroke of the displacing member, and means for compensating for the wear on the active peripheral portion of the driven gear.

5. A fuel pump for delivering fuel to the carburetor of an internal combustion engine, comprising a chamber having inlet and outlet ports, a pumping member in the chamber movable on one stroke to intake fuel from a source of supply and on its next, stroke to expel fuel to the carburetor, resilient means for actuating the pumping member on one stroke and mechanical means for positively actuating the pumping member on its reverse stroke, said mechanical means including a pair of rotatable members, one of which has an active portion extending partially thereabout and adapted to be brought into functioning relation to the other of said rotatable members by said resilient means upon the latter imparting its full stroke to said pumping member, said active portion riding out of functioning relation to said other rotatable member to permit the functioning of the resilient means.

6. A fuel pump having piston means operating in a chamber thereof with a liquid expelling stroke and a return liquid intaking stroke, a piston actuating rod operating in a hearing which opens into an adjacent reservoir whereby leakage of fuel from the pump chamber through said hearing will enter the reservoir, resilient means for yieldably imparting the liquid expelling stroke to the piston, a driving gear, a driven gear for meshing contact with the driving gear, said driven 5 gear having a mutilated peripheral portion for non-engagement with the driving gear co-extensive substantially with the liquid expelling stroke of the piston, said driven gear also having an active peripheral portion for driving engagement with the driving gear to be driven thereby to im- \rt the return stroke to the piston, and means operatively connecting the driven gear to the.

piston rod, said means acting to move the driven gear .ito reengagement with the driving gear under the urge of said resilient means and substantially at the completion of the liquid expelling stroke of the piston.

'7. A fuel pump for delivering fuel to the carburetor of an internal combustion engine, comprising a. chambei having inlet and outlet ports, a pumping member in the chamber movable on one stroke to intake fuel from a source of supply and on its next stroke to expel fuel to the carburetor, means for urging the pumping member on its expelling stroke in accordance with the engine demands, and means for automatically driving the pumping member from the engine on its intaking stroke,' said means including a pair of rotatable members one of which is freely movable with respect to the other during the expelling stroke and engageable with said other member for driving the pumping member on its intaking stroke at the completion of its expelling stroke.

8. A fuel pump for transferring fuel from a supply to an engine embodying a liquid displacing means operable on a fuel expelling stroke to feed fuel to the engine and on a return stroke to intake fuel from the supply, yieldable means for actuating the displacing member on its fuel expelling stroke in response to engine needs, a rotatable driven means operably connected to saidliquid displacing means, said driven means having a peripheral portion operably engageable with a drive means for positively actuating said displacing means on its fuel intaking stroke and a peripheral portion non-engageable with the drive means during actuation of said displacing means by said yieldable means, and a drive means for operating said driven means when engaged therewith by said yieldable means substantially upon completion of the fuel expelling stroke.

9. In a pump for transferring fuel to the float chamber of a carburetor and maintaining a predetermined level therein, a rotatable drive member having a continuous driving surface, a rotatable driven member engageable with the drive member, said driven member being of a form to engage with said drive member for being posimember during the remaining portion of the full V movement of said driven member.

10. In a fuel pump, a chamber, a fluid displacing wall operably mounted therein, a yieldable member mounted for operating said wall in a fluid expelling stroke, a rotatable driven means for positively operating said wall-in a fluid intaking stroke substantiallyupon completion of said expelling stroke, means'operably connecting said wall to said driven means, a rotatable drive means for driving said driven means, said driven H means including a portion disengageable from ERWIN c. HORTON. 

